DE1770754A1 - Production of polyamides with special properties - Google Patents

Description

Production of polyamides with special properties The invention relates to the production of polyamides with special properties.

It is known that the properties of the polyamides can be increased by adding all kinds of substances for these polyamides or for polyamide-forming compositions to be influenced. For example, substances that cannot be mixed homogeneously with polyamide can be mixed with polyamide Polyamide are distributed (see the American patent specification 2,205,722), whereby matt-glossy polyamides are formed. Pigments and antioxidants can also be used (see American Patent 2,510,777). Also can by adding stabilizers (American patent specification 2,887,462) the light resistance of the polyamides can be improved.

Inside polyamide threads with special properties are obtained, by making two or more spinnable polyamide compositions of one another deviating composition in direct contact simultaneously to heterogeneous thread spun (Belgian patent 815.857).

It has now been found that polyamides have special properties if in a polyamide-forming composition before or during their polymerization or in a polyamide at least one representative of the lysine, α-Amino-C-caprolactam, # -N-R-lysine (where R is a divalent hydrocarbon radical represents), a-N-R-a-amino-ewcaprolactam (where R is a divalent hydrocarbon radical represents), N, N '-Bis (hexahydro-azepin-2-oxo-3-yl) -R (where R is a diamine or a Represents diamide) and 1 N, 3 N, 5 N-tri (hexahydro-azepin-2-oxo-3-yl) -triazin-1, 3.5 existing group, is distributed.

The additives used according to the invention except lysine and a-amino-C-caprolactam, belong to the general class of Schiff bases and can use the well-known methods, such as those described in Houben Weyl, Methods of Organic Chemie, Volume 11, Part 2, pages 77 and 78 (1958).

Examples of these additives are: c-N-methylene lysine, a-N-methylene-α-amino - # - caproactam, N, N 'N'-bis (hexahydro-azepin-2-oxo-3-yl) -methylenediamine, N, N'-bis (hexahydro-azepin-2-oxo-3-yl) -p-xylylenediamine, N, N'-bis (hexahydro-azepin-2-oxo-3-yl) succinic acid diamide and mixtures of these substances.

Even small amounts of the substances to be added according to the invention (e.g. 0.5, 1.5, 3 or 5% by weight, based on the polyamide) result in polyamides which have special properties and are usually spun into threads in the usual way can be.

By adding larger quantities of these substances to polyamides or polyamide-forming substances Compositions are obtained modified polyamides, e.g. from laurolactam or mixtures of lactams from which molded articles can be made.

The properties of the polyamides thus obtained are given in the examples explained in more detail.

Examples 1- VIII Polymerization tests are carried out in a comparable manner carried out in which # -caprolactam with an invention to be added Substance is mixed. At the same time, 4% by weight of water are used to promote the polymerization and in some cases 0.015 wt% acetic acid is added. The polyamide-forming composition is for 16 hours at a temp. of 260 OC in a nitrogen atmosphere at heated to atmospheric pressure.

The polyamide is then extruded into thread. After washing out the viscosity is measured with methanol. The table below shows the results.

The additives identified in Table 1 by A, B, C, D and E are: Additive A: NJNi-bis (hexahydro-azepin-2-oxo-3-yl) -p-xylylenediamine Additive B: N, N'-Bis (hexahydro-azepin-2-oxo-3-yl) succinic acid additive C: a mixture of approximately equal amounts by weight of α-N-methylene-α-amino - # - caproactam, N, N'-bis (hexahydro-azepine- 2-oxo-3-yl) methylenediamine and 1 N, 3 to N, 5 N-tri (hexahydro-azepin-2-oxo-3-yl) -triazine-1, 3, 5 additive D: # -N- Methylene lysine additive E: α-amino - # - caprolactam The designation # -rel., Ie the relative viscosity, is understood to mean the viscosity of a solution of 1 g of polyamide in 100 ml of sulfuric acid (96% by weight) at 20 ° C, based on the viscosity of sulfuric acid. Example additive water acetic acid No. (% by weight) (% by weight) (% by weight), -rel. - 4 - 2.7 4 4 0.015 2.4 I 1% lysine 4-2.6 II 5% lysine 4 - III 1% A @ 4 0.015 2.7 IV 3% A 4 0.015 3.6 V 1% B 4 0.015 2.6 VI 2% C 4 0.015 2.8 VII 1% D 4 0.015 2.8 VIII 1% E 4 - 2.6 The viscosity values show that polyamides are obtained which can be spun into threads. The polyamide obtained in Example II with an addition of 5% lysine does not dissolve in sulfuric acid, while the melted product is so liquid that spinning cannot be carried out.

Dyeing tests were carried out with the polyamides obtained in this way.

These showed that from the compositions according to the invention Polyamide threads formed showed a far more intense color than those made from products without additives. The improved colorability and color intensity can be Use with advantage in the production of polyamide-containing fabrics with special Color effects.

Example IX The polymerization of caprolactam takes place in one Autoclave in which the polyamide-forming composition is in a nitrogen atmosphere at a temperature of 260 ° C and a pressure of 5-6 at. Heated for 3 hours will. The pressure is then reduced to 1 atm by removing the gaseous products and then it is heated for three hours at 260 ° C. The so pure Product is also extruded into a thread. After washing with methanol is the viscosity measured.

In this way, lactam compositions enriched with lysine, which furthermore 14.7 mol.% water and 0.15 mol.% acetic acid (except in the following Cases) contain polymerized.

The relative viscosity of the polyamide products obtained is: with 0.7 wt.% Lysine: 2.8 with 1 wt.% Lysine: 2.9 with 2 wt.% Lysine (without acetic acid): 3.1 with 3% by weight of lysine (without acetic acid): 2.9 The mechanical properties of Polyamide with a lysine addition of 1% by weight are: Tensile strength 7.5 - 9 (8 - 9) g / denier elongation at break 15 - 17 (14-15)% modulus of elasticity 55 - 65 (45-55) "elastic creep strain" 1.2 - 1.4 (2.0-2.3) mm The values between brackets refer to the values found with products without added lysine.

The "elastic creep strain" is determined by adding a Thread bundles of the material to be tested of 1680 denier at a temperature of 23.9 OC and a relative humidity of 55%. At the free end of the hanging bundle (length 50 cm) 30th A load of 1,362 kg hung for minutes. After measuring the length (a) a Part of this load, namely 0.908 kg, so that 0.454 kg remains. This residual load is maintained for 2 hours.

Then the load is increased again up to 1.362 kg, whereupon after 12 sec the length (b) is measured again, the difference between the two Length measurements (a) and (b) are given as "elastic creep strain" in mm.

The value of this proportion of creep strain is important for the application this polyamide as an insert in fabrics for tires, especially car tires. For For this purpose, the proportion of creep strain should be as low as possible.

From the values mentioned in Example IX, it follows that a reduction the proportion of creep strain is present, while the modulus of elasticity experiences an improvement.

Claims (1)

PATENT CLAIMS Process for the production of polyamides with special Properties, characterized in that in a polyamide-forming composition at least one representative before or during their polymerization or in a polyamide that of lysine, α-amino-c-caprolactam, C-N-R-lysine (where R is a divalent hydrocarbon radical represents), a-N-R-OTAmino-e-caprolactam (where R is a divalent hydrocarbon radical represents), N, N'-bis (hexahydro-azepin-2-oxo-3-yl) -R (where R is a diamine or a Represents diamide) and 1 N, 3 N, 5 N-Tri (hexahydro-azepin-2-oxo-3-ylftriazin-1, 3, 5 existing group is distributed.